Subject: Number 108 in the Series--North American F-108 Rapier

From: [email-masked] (Steve Bridges)
Date: 2 Mar 94 17:21:54 GMT

>From 

The F-108A Rapier was destined to be the last fighter project carried 
out by North American Aviation, builders of such immortals as the P-51 
Mustang and the F-86 Sabre.  

The F-108 project was originally known as the LRIX (Long-Range 
Interceptor, Experimental) and was initiated by the Air Force on 
October 6, 1955.  On June 6, 1957, North American was issued a letter 
contract for two prototypes of a long-range, high-performance 
interceptor to be designated F-108A.  The company designation for the 
aircraft was NA-257.  It was to be capable of Mach 3 performance and 
was intended to serve as a long-range interceptor that could destroy 
attacking Soviet bombers over the poles before they could get near US 
territory.  It was also to serve as the escort fighter for the XB-70 
Valkyrie Mach-3 strategic bomber, also to be built by North American.  
The Air Force expected that the first F-108A would be ready for 
service by early 1963.  An order for no less than 480 F-108s was 
anticipated.  

The F-108A design that North American ultimately produced called for a 
large delta-winged aircraft powered by a pair of afterburning General 
Electric J93-GE-3AR turbojets fed by variable inlets mounted 
underneath the wing roots.  The F-108 aircraft was designed for a 
maximum speed of 1980 mph at 75,550 feet and for a 1020-mile combat 
radius.  The pilot and radar operator sat in tandem individual ejector 
capsules in the forward cockpit.  The aircraft was to be equipped with 
an extremely sophisticated avionics system, directed by the Hughes 
AN/ASG-18 search and tracking radar which was to have a range of over 
100 miles.  

The F-108A was to be armed with three advanced Hughes GAR-9 Falcon 
missiles housed in an internal weapons bay.  The GAR-9 missile was 
powered by a Lockheed storable liquid-propellant rocket motor which 
was capable of driving the missile to hypersonic speeds of up to Mach 
6 and achieving ranges of up to 115 miles.  The GAR-9 missile used 
semiactive radar homing for midcourse guidance, with passive infrared 
homing being used for the final run-in to the target.  

A mockup was inspected in January 1959, with the initial flight being 
planned for March 1961.  The popular name *Rapier* was assigned on May 
15, 1959.  

However, by mid 1959, the Air Force was already beginning to 
experience some doubts about the high cost of the Rapier program.  The 
primary strategic threat from the Soviet Union was now perceived to be 
its battery of intercontinental ballistic missiles instead of its 
force of long-range bombers.  Against intercontinental ballistic 
missiles, the F-108A interceptor would be completely useless.  In 
addition, the Air Force was increasingly of the opinion that unmanned 
intercontinental ballistic missiles could accomplish the mission of 
the B-70 Valkyrie/F-108 Rapier combination much more effectively and 
at far lower cost.  Consequently, the F-108A project was cancelled in 
its entirety on September 23, 1959, before any prototypes could be 
built.  The XB-70 project was also halted, and on December 3, 1959 was 
cut back to only one prototype.  

The work on the Rapier did not entirely go to waste.  The work that 
Hughes did on the AN/ASG-18 radar was later transferred over to the 
Lockheed YF-12A interceptor project, and the GAR-9 Falcon 
(redesignated AIM-47A in 1962) missile originally developed for the 
F-108A was used to arm the YF-12A.  

Specification of F-108A Rapier (estimated): 

Two General Electric J93-GE-3AR turbojets, 20,900 lb.s.t. dry, 30,000 
lb.s.t. with afterburner.  Maximum speed: 1980 mph at 76,550 feet.  
Service ceiling 80,100 feet, combat ceiling 76,550 feet.  Initial 
climb rate 18,000 feet per minute.  Climb to 50,000 feet in 5.4 
minutes.  Combat radius 1020 miles with three missiles.  2488 miles 
ferry range.  Dimensions: wingspan 57 feet 5 inches, length 89 feet 2 
inches, height 22 feet 1 inches, wing area 1865 square feet.  Weights: 
50,907 pounds empty, 76,118 pounds combat, 102,533 pounds gross.  Armed 
with three Hughes GAR-9 Falcon air-to-air missiles.  

Sources:

  The American Fighter, Enzo Angelucci and Peter Bowers, Orion, 1987.

  Fighters of the United States Air Force, Robert F. Dorr and
  David Donald, Temple Press Aerospace, 1990.

  American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday,
  1982.

  Post-World War II Fighters, 1945-1973, Marcelle Size Knaack,
  Office of Air Force History, 1986. 

Joe Baugher		AT&T Bell Laboratories   	
2000 North Naperville Road      Naperville, Illinois 60566-7033